Dear Suresh I faced the same problem. to deal with this, please uninstall mpi(if you use it) and install older version. then configure and makeall espresso again for this.
2015-08-11 16:58 GMT+03:00 Axel Kohlmeyer <[email protected]>: > On Tue, Aug 11, 2015 at 7:01 AM, Suresh A <[email protected]> > wrote: > > Respected Sir/Friends, > > I have formed a PC beowulf cluster (X86_64 old PC's > made > > on 2007) and installed quantum espresso-5.2.0 in it. Now the cluster is > > running very slowly than the single core i5 processor, DDR3 RAM with > 1600MHZ > > speed. The following is my observation in single core i5 processor and in > > beowulf cluster for the titanium dioxide supercell of size 2x2x1. One > more > > thing is, in cluster every node has 2GB DDR2 RAM with speed 667 MHZ. for > i5 > > processor 8GB with 1600 HZ. > > > > total cpu time spent upto now is 408.7 secs (for i5 CPU having > > 1600MHZ) > > > > total cpu time spent upto now is it is keepon running more than 1 hour > > (for one single processor in PC cluster) > > > > total cpu time spent upto now is 1402 secs ( for -ni 10 -nk 10 in PC > > cluster) > > > > > > > > Is this due to RAM speed, size or anything else? > > it is due to *everything*: clock rate, memory speed, memory > architecture, processor architecture, processor cache size, disk > caching efficiency, availability of SIMD instructions, compiler, > libraries. > the speed difference you quote seems quite normal for comparing a > single core on current hardware versus 8 year old hardware. > > axel. > > > > > Looking forward to your valuable suggestions > > > > With Regards, > > A.Suresh, > > Research Scholar, > > Madurai Kamaraj University, > > Madurai. > > > > _______________________________________________ > > Pw_forum mailing list > > [email protected] > > http://pwscf.org/mailman/listinfo/pw_forum > > > > -- > Dr. Axel Kohlmeyer [email protected] http://goo.gl/1wk0 > College of Science & Technology, Temple University, Philadelphia PA, USA > International Centre for Theoretical Physics, Trieste. Italy. > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum >
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